This invention relates to a connector structure having a short-circuiting member for removing a potential difference between terminals.
In a circuit in which a load and a power source are connected together by a connector, an electric current may be induced in a load-side circuit by electromagnetic waves and static electricity when the connector is not in a connected condition. In this case, due to the difference in current intensity between signal lines, there is a possibility that a voltage develops between the signal lines, so that an equipment (load) is subjected to a malfunction. For example, in an air bag circuit in which an ignition signal is fed to an ignition device so as to inflate an air bag, such a situation should be avoided by all means so as to secure safety during the travel.
A connector structure, having a short-circuiting member for removing a potential difference between terminals, will be described with reference to FIGS. 8 to 10 (the connector structure shown in FIGS. 8-12 are not prior art for the present application). FIG. 8 is a cross-sectional view of the connector structure having the short-circuiting member, FIG. 9 is an exploded, perspective view of an important portion of the connector structure, and FIG. 10 is a cross-sectional view showing a condition in which terminals and an insulating plate of a mating connector are inserted into the connector of FIG. 8.
Terminal receiving chambers 3 are formed in a housing 1, and are open at one end thereof to a front surface of the housing 1 to form connection ports 5 for receiving the mating terminals, and are also open at the other end thereof to a rear surface of the housing 1 to form mounting ports 9 for receiving terminals 7. An elastic retaining piece portion 11 is provided in the terminal receiving chamber 3, and is retainingly engaged in an engagement hole 13, formed in the terminal 7, to retain the terminal against withdrawal. The terminals 7 are connected, for example, to an air bag ignition device (load).
A short-circuiting member 15, made of an electrically-conductive metal sheet, is mounted below the terminal receiving chambers 3 (that is, at a lower portion in FIG. 8). As shown in FIG. 9, the short-circuiting member 15 has a pair of contact plate portions 17 and 17. The contact plate portions 17 and 17 project respectively into the juxtaposed terminal receiving chambers 3 provided in the housing 1. Each of the contact plate portions 17 and 17 has a mountain-like shape having a peak at its central portion, and has front and rear slanting surfaces 19a and 19b.
The short-circuiting member 15 is attached to the housing 1 before mounting the terminals 7. When each terminal 7 is inserted into the associated terminal receiving chamber 3, the terminal 7 first abuts at its distal end against the slanting surface 19b, and forces the contact plate portion 17 out of the terminal receiving chamber 3, so that the contact plate portion 17 is held in press-contact with the terminal 7, as shown in FIG. 8.
Therefore, the pair of terminals 7 and 7, received respectively in the pair of terminal receiving chambers 3, are electrically connected together by the short-circuiting member 15, thereby removing a potential difference between the terminals in a non-connected condition of the connector. As shown in FIG. 10, the mating connector, connected to a power source, includes projecting terminals 21 and an insulating plate 23, and when the two connectors are connected together, the insulating plate 23 is inserted between the pair of terminals 7 and 7 and the pair of contact plate portions 17 and 17.
In the above connector structure related to the present invention, the terminals 7 and 7 are connected to a power source-side circuit when the two connectors are connected together, and when the two connectors are not connected together, the terminals 7 and 7 are short-circuited together, thereby removing a potential difference therebetween, thus positively preventing a malfunction of the electronic circuit.
In the above related connector structure, however, the contact plate portions 17 of the short-circuiting member 15 project far into the respective terminal receiving chambers 3 as shown in FIGS. 11 and 12 so that they can contact the respective terminals 7 with a sufficient contact pressure, and therefore when the terminal 7 is inserted, the distal end of the terminal 7 sometimes fails to properly abut against the slanting surface 19b of the contact plate portion 17 as shown in FIG. 11, and forces the contact plate portion 17 upward, which leads to a possibility that the terminal 7 or the contact plate portion 17 is damaged. To avoid this, if the amount of projection of the contact plate portion 17 into the terminal receiving chamber 3 is reduced, the load (or pressure) of contact of the contact plate portion 17 with the terminal 7 is reduced, which causes the increase of a resistance or the incomplete contact.